Mitsubishi Montero (2002-2004). Manual - part 715

TSB Revision

DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-557

DTC P1400: Manifold Defferential Pressure Sensor Circuit Malfunction

CIRCUIT OPERATION

• A 5-volt voltage is applied on the manifold differ-

ential pressure sensor power terminal (terminal
No. 3) from the PCM (terminal No. 106). The
ground terminal (terminal No. 2) is grounded with
the PCM (terminal No. 105).

• A voltage proportional to the pressure in the

intake manifold plenum is sent from the manifold
differential pressure sensor output terminal (ter-
minal No. 1) to the PCM (terminal No. 101).

BLA

GREEN-YELLO

BLUE-YELLO

AK201150

5 V

101

POWERTRAIN CONTROL MODULE (PCM)

2 3

B-28

(MU802723)

MANIFOLD DIFFERENTIAL
PRESSURE SENSOR

Manifold Differential Pressure Sensor Circuit

9192

939495

96979899

100

105

113114

115116117

118119120

106

107108109

110111112

101102103

104

D-135

(MU803805)

AK200974

MANIFOLD
DIFFERENTIAL
PRESSURE
SENSOR

B-28(B)

CONNECTOR: B-28

AK201038AF

CONNECTOR: D-135

PCM

D-135(GR)

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DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-558

TECHNICAL DESCRIPTION

• The manifold differential pressure sensor outputs

a voltage which corresponds to the negative
pressure in the intake manifold.

• The PCM checks whether the voltage output by

manifold differential pressure sensor is within a
specified range.

DTC SET CONDITIONS

Check Conditions

• 8 minutes or more have passed after starting the

engine. Note that this is only if the engine coolant
temperature is less than 0

°C (32°F) when start-

ing.

• Engine coolant temperature is higher than 45°C

(113

°F).

• Intake air temperature is higher than 0°C (32°F).

• Volumetric efficiency is between 30 and 55 per-

cent.

Judgment Criteria

• Manifold differential pressure sensor output volt-

age has continued to be higher than 4.6 volts
[corresponding to an absolute pressure of 118
kPa (17 psi) or higher] for 2 seconds.

• Manifold differential pressure sensor output volt-

age has continued to be lower than 0.1 volt [cor-
responding to an absolute pressure of 2.4 kPa
(0.3 psi) or lower] for 2 seconds.

Check Conditions

• 8 minutes or more have passed after starting the

engine. Note that this is only if the engine coolant
temperature is less than 0

°C (32°F) when start-

ing.

• Engine coolant temperature is higher than 45°C

(113

°F).

• Intake air temperature is higher than 0°C (32°F).

• Volumetric efficiency is lower than 30 percent.

Judgment Criteria

• Manifold differential pressure sensor output volt-

age has continued to be higher than 4.2 volts
[corresponding to an absolute pressure of 108
kPa (16 psi) or higher] for 2 seconds.

Check Conditions

• 8 minutes or more have passed after starting the

engine. Note that this is only if the engine coolant
temperature is less than 0

°C (32°F) when start-

ing.

• Engine coolant temperature is higher than 45°C

(113

°F).

• Intake air temperature is higher than 0°C (32°F).

• Volumetric efficiency is higher than 70 percent.

Judgment Criteria

• Manifold differential pressure sensor output volt-

age has continued to be lower than 1.8 volts [cor-
responding to an absolute pressure of 46 kPa
(4.6 psi) or lower] for 2 seconds.

TROUBLESHOOTING HINTS (The most likely
causes for this code to be set are: )

• Manifold differential pressure sensor failed.

• Open or shorted manifold differential pressure

sensor circuit, or loose connector.

• PCM failed.

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DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-559

DIAGNOSIS

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check data list item 95:
Manifold Differential Pressure Sensor.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991502 to the data reading mode for item

95, Manifold Differential Pressure Sensor.

• While engine is idling, pressure should be between 20.6

− 34.0 kPa (6.1 − 10.0 in.Hg).

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : This malfunction is intermittent. Refer to GROUP 00,

How to Use Troubleshooting/Inspection Service
Points

P.00-6

NO : Go to Step 2.

STEP 2.Check harness connector B-28 at manifold
differential pressure sensor for damage.
Q: Is the harness connector in good condition?

YES : Go to Step3.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection. Then go to Step12.

ACX01539

16-PIN

MB991502

AK200975

HARNESS
CONNECTOR:
COMPONENT SIDE

CONNECTOR: B-28

B-28(B)

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DIAGNOSTIC TROUBLE CODE PROCEDURES

13Ac-560

STEP 3. Measure the sensor supply voltage at manifold
differential pressure sensor harness side connector B-28.
(1) Disconnect the connector B-28 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal No. 3 and ground.

• Voltage should be between 4.8 and 5.2 volts.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.8 and 5.2 volts?

YES : Go to Step 6.
NO : Go to Step 4.

STEP 4. Check harness connector D-135 at PCM for
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 5.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 12.

AK200975

HARNESS
CONNECTOR:
COMPONENT SIDE

CONNECTOR: B-28

B-28(B)

AK000200 AC

B-28 HARNESS
CONNECTOR:
COMPONENT SIDE

AK200947

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

CONNECTOR: D-135

HARNESS CONNECTOR:
COMPONENT SIDE

PCM

D-135(GR)

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